Coal mining machine



Oct. 23, 1951 M. R. STEVENSON 2,572,403

COAL MINING MACHINE Filed Oct. 25, 1948 2 SHEETS-SHEET l INVENTOR. MERE/N R STt-Mf/YSO/Y.

Oct. 23, 1951 M. R. STEVENSON 2,572,403

COAL MINING MACHINE I Filed Oct. 25, 1948 2 SHEETSSHEET 2 IN VEN TOR.

ATTORNEY.

Patented Oct. 23, 1951 UNITED- STATES: PATENT OFFICE.

1. This inventionrelates to a method-" L and apparatusfor; mining coal or similar materials, and

more particularly to a boring head fonboring' into a wall of coal.

The principal object ofthe' invention provide a boring head whichwill simultaneouslycut and break the :coal from the vein ready for haulage.

Another: object-is toso'econstru'ct' ther'device that it can be appli'edto present rail supported; coal cutting machines; and sothat it can'be operated at any desired height or atany desired angle so as to obtain full-advantage'of 'thet-position ofthe-coal.

Another object ofthe invention is." to provide 1 a-method of mining coal wherein-relatively large; round bore are made: into 1 the: coal at spaced intervals so that the intervening coal between: the bores can b'e'1readilybroken' down.

Other objects and: advantages: reside in the detail construction of the invention; which-is designed forfsimplicity, economy; and efficiency. These will become more'iap'parent from" the:fol-=- lowing description.

In thev following detailedi. description of the invention,1.reference" is. had to the accompanying drawing which formsa part hereof; Likenu merals refer to like partsin' all views of the drawing and: throughout the; description;

In the drawings Fig; 1 is a side elevation} illustrating-the invention applied to a typical Universal coal cutter. such as used in coal mines Fig. 2. is av front view of: theimproved boring" head, looking-in the direction'of the arro-w 2*"" in Fig.1

Fig; 3 is an enlarged; longitudinal section through the-boring:head taken onth'eline 3"-'--3. Fig. 2.;

Fig. .4-' isza stillfurther enlarged; detail, hori zontalsection; taken on. thelineL-l; Fig. 3: and

Fig. 5 is a similarly enlarged top view of the improved boringhead, looking: in the direction of arrow 5 in Fig. 3.

In Fig; 1 a" typical-universal coal cutter'is illustrated, of the type k no'wn in theart as the- Jetfrey' 29-U.' Coal icutters' of this 'typeiare' mount; ed on a truck I8 supporting aturntable' II and a motor'and reel'box l2; Aboom; l3 is mounted on I a: horizontal hinge l l onthe; turntable H i so that it may be r'aised and lowered through the medium of hydx aulic 'jack's l-5 Theboom- I3'is provided with hydraulic motors for rotating a cutter bar and for 'rotating a tubular'housing aboutthecutter bar; The cutter bar 65'- 5':CIaims:. (Cl. 262-9 2 in the usua-Icoalcutter operates an elongated, flat cutter'h'e'ad' for shearing or cutting slots in the coal; cutter'head'with its cutter bar and sleeve are removed'and'the'improved boring head is applied in their stead.

Theimp'roved'boring head 'is provided with a tubulansupporting shaft l6 which replaces the sleeve of the usual'cutter head, and which is rotated by the mechanism ihthe boom l3 which rotates: the sleeve'of the usual head. A central shaft l1 passesthrough the tubular shaft l6 and replaces the usual cutter bar of the conventional coal cutter.

Thehydrauli'c'motors in the boom l3 rotate the tubular shaft lfi'and'theshaft" I! under the same controls and bymeans'ofthe same mechanism that formerly operated the cutting chain and boring bar offtheusual coal cutter.

This; invention relates more particularly to This 25: tachment flange 2 0.

The tubular shaft l6 is provided at its'outer extremity with an inclined flange 2| against which the flange I9.isbolted by means of suitable cap screws orbolts '22. tions the axes of the'housing IB' and the shaft I6 softhat they will 'intersect each other at an angle ofapproximately 10, as shown in Fig. 3.

A stub shaft 23 'isrotatablymounted in suitable anti-friction bearings '24 inthe housing I8.

The stub shaftcarrie's adriven bevelgear 25 at itsinner'extremity,which is in constant mesh with: a drivebevel gearZ 6" on the extremity'of the shaft IT. The shaft I1 is rotatably and axially mounted in the tubular Jshaft l 6 in suitable antifriction' bearings 21!.

A breaking :blade '28'=is mounted on the forward flange ZU'of" the housing l8. by means of cap screws 29. swings spirally rearward, similarlycto theiblade of an auger orboringbit;

In' applying this invention, the usual This arrangement posi- The outer edge of the breaking blade i 3 35 is threaded into the block 34 and bears at its outer extremity against the block 33 so that the block 33 can be forced outwardly to increase the tension in the chain 30.

The tension screw 35 is provided with a Wrench portion 4| which is accessible through an opening 42 in the plate 36.

The block 34 is rigidly mounted between an outside chain-retaim'ng plate 36 and an inside chainretaining plate 31. The plates '36 and 31 are elongated and provided with rounded extremities to conform to the path of, and to slidably support, the chain 30. The plates are rigidly at tached in place by means of attachment screws I 38 which pass the outer plate 36, and are thread ed into the breaking blade 28.

said blade extending spirally rearward; an end- The block 33 is adjustably supported between the plates 36 and 3'! by means of clamp screws 39 which pass through the outer plate 33 and."

through elongated slots 40in the block 33, thence through the inner plate 31 and are threaded into the breaking blade 28. The'elongated slots 40 serve'to allow outward and inward movement of the'block 33 under the influence of the screw 35.

'It can be readily seen that as the tubular shaft I6 is rotated by the hydraulic motors in the boom 13, the axis of the housing I8 will gyrate in a conical path, carrying the breaking blade forwardly in the direction of the arrow in Fig. 2.

It will be noted that, due to the incline of the blade 28 and to the incline of the shaft 23, the entering edge of the blade 28 will be positioned well forward of the trailing edge thereof. The entering edge carries the coal-cutting chain 30, and this chain is rotating at higher speed than the tubular shaft [6, since the construction of the conventional coal cutter rotates the shaft M at higher speed.

Thus, it will be seen that the teeth 3| will cut a channelin the coal and, as the entering edge rotates the entering edge of the blade 28 will enter this channel, and the rearward incline of the blade 28 will break the coal from the channel outwardly so as to rapidly bore a hole on a relatively steep helix while simultaneously breaking the coal backwardly between the cuts of the helix.

The entire coal face canbe rapidly removed by asimple boring operation, or the face may be bored at spaced-apart points in the face, and the coal between the bores may be broken down.

The construction of the coal cutter illustrated in Fig. l'allows the boring head to be raised and lowered from the floor to a height to out eight feet above the floor, and the boom I3 may be swung from side to side to cover a width of fifteen feet. The breaking blade 28 is advanced into the coal face by the natural incline of the breaking blade and by the self-propelling of the truck Ill forwardly. The boring head may be made in any size. As illustrated, it is designed to bore ahole in the coal approximately four feet in'diameten.

While a' specific form of the improvement has been described and illustrated herein, it is to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. A boring head for coal cutting machines comprising: a shaft housing; a stub shaft rotatably mounted in said shaft housing; a spirally inclined breaking blade fixedly mounted on the forward face of said housing the outer edge of said less coal cutting chain positioned at the entering edge of said blade so as to cut a slot for the blade to enter; a chain sprocket on said stub shaft supporting s'aid chain; a tubular shaft connected to and supporting said housing; so as to position the stub shaft so that its axis will intersect the axis ofsaid tubular shaft at an acute angle; an axial drive shaft in said tubular shaft and driving said stub shaft; and-*means for rotating said tubular shaft and said central shaft independently of eachother. I

3. A boring head for coal cutting machines comprising: a shaft housing; a stub shaft rotatably mounted'in said shaft housing; a spirally inclined breaking blade fixedly mounted on the forward face of said housing the outer edge of said blade extending spirally rearward; an endless coal cutting chain positioned at the entering edge of said blade so as to cut a slot for the blade to enter; a chain sprocket on said stub shaft supporting said chain; a tubular shaft connected to and supporting said housing so as to position the stubshaft so that its axis willintersect the axis of said tubular shaft at an acute angle; an axial drive shaft in said tubular shaft; bevel gears connecting said drive shaft to said stub shaft; and means for independently rotating said drive shaft and said tubular shaft in thesame direction and at differing speeds.

.4. A coal cutting device comprising: a tubular shaft; an axial shaft passing axially through said tubular shaft; means hingedly supporting one extremity of said tubular shaft; means for swinging the other extremity of said tubular shaft about said'hinge means; a head member secured to the free extremity of said tubular shaft; a breaking blade mounted on said head member the outer edge of said blade extending spirally rearward; a sprocket shaft in said head member; a sprocket on the forward extremity of said sprocket shaft; an endless coal cutting chain trained about said sprocket and positioned at the entering edge of said breaking blade to cut a path for the latter; and means for rotating said tubular shaft and said axial shaft at different speeds in a common direction, the axis of said sprocket shaft intersecting the axis of said axial shaft at an angle i pp m ly 1 and means transmitting 'the rotation of said axial shaft to said sprocket shaft.

A coal cutting device comprising: a tubular shaft; an axial shaft passing axially through said tubular shaft; means hingedly supporting one extremity of said tubular shaft; means for swinging the other extremity of said tubular shaft about said hinge means; an inclined flange at the free extremity of said tubular shaft; a head housing secured on said inclined flange so as to posi-- tion its axis at an angle to the axis of said tubu-- lar shaft; an inclined attachment flange at the.

forward face of said housing; a breaking blade secured on the forward face of said attachment flange; an inside chain retaining plate secured 5v against said breaking blade; a stub shaft extending through said breaking blade and said retaining plate; a chain sprocket mounted on the forward extremity of said stub shaft; a separating block positioned adjacent said sprocket; an arcuate tension block positioned alongside said separating block; an endless coal cutting chain trained around said sprocket and said tension block; means for separating said tension block from said separating block to increase the tension in said chain; an outer chain retaining plate covering said sprocket and said blocks; means transmitting rotation from said axial shaft to said stub shaft; and means for rotating said tubular shaft and said axial shaft, said cutting chain being positioned at the entering edge of said breaking blade so as to cut a slot for said blade to enter,

the outer edge of said blade extending spirally rearward so as to break the coal rearward from said slot.

MERLIN R. STEVENSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

